[solved] Pupil size obtention
Hi,
I want to obtain the pupil size of my subject, and to do this I have made the following modifications to Libtobii.py, in the flushData(self) function :
- addition of 'L.PupilSize' and 'R.PupilSize' in self.datafile.write('\t'.join(['TimeStamp',
- addition of g.LeftPupil ande g.RightPupil in self.datafile.write('%.1f\t%.4f\t%.4f\t%d\t%.4f\t%.4f\t%d\t%d\t%d'%(
The function now looks like :
self.datafile.write('\t'.join(['TimeStamp',
'GazePointXLeft',
'GazePointYLeft',
'ValidityLeft',
'GazePointXRight',
'GazePointYRight',
'ValidityRight',
'L.PupilSize',
'R.PupilSize',
'GazePointX',
'GazePointY',
'Event'])+'\n')
# time of the first event
timeStampStart = self.gazeData[0].Timestamp
# loop through all data points
for g in self.gazeData:
# write timestamp and gaze position for both eyes to the datafile
self.datafile.write('%.1f\t%.4f\t%.4f\t%d\t%.4f\t%.4f\t%d\t%d\t%d'%(
(g.Timestamp-timeStampStart)/1000.0,
g.LeftGazePoint2D.x*self.disp.dispsize[0] if g.LeftValidity!=4 else -1.0,
g.LeftGazePoint2D.y*self.disp.dispsize[1] if g.LeftValidity!=4 else -1.0,
g.LeftValidity,
g.RightGazePoint2D.x*self.disp.dispsize[0] if g.RightValidity!=4 else -1.0,
g.RightGazePoint2D.y*self.disp.dispsize[1] if g.RightValidity!=4 else -1.0,
g.RightValidity,
g.LeftPupil,
g.RightPupil))
My problem is that in the output file colums of R.PupilSize and L.PupilSize I have only '3' or '4' when the sample is valid, -1 if not.
What is my mistake ? Why don't I obtain a pupil size ?
Thanks for any help !
Comments
I finally found the error...
t%d was just not the good way to treat the value as a decimal, I replace it by t%.4f and it works fine.
'3' and '4' were just the whole part of the pupil size.
Sorry for the useless question.
Hi,
Indeed,
%dis for integers, and will effectively roundfloats down.Btw, if you feel that this a wortwhile addition to PyGaze that other people might benefit from as well, you could consider sending Edwin a pull request with the changes through GitHub. The repository is here:
Cheers!
Sebastiaan
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This is brilliant, thanks for adding this clearly important feature I neglected!
Hi @Edwin , I was wondering if this feature is included in the latest version of PyGaze. I also found it'd be very helpful to record pupillary data. I believe that in my current version, pupil size is included for the eye tribe tracker output but not for tobii ouput.
Thanks,
Han
Hi @hanzh,
Yes, it should be possible! What Tobii back-end are you using? Are you using
tobiiortobii-legacyin the latest version of PyGaze, or perhaps using an older version that only hastobii(which is the currenttobii-legacy)?Edit: I just checked, and the functionality above was never pull-requested into the
tobii-legacyback-end. It should be supported by thetobiiback-end, I believe, which is based on the new Tobii Pro SDK. If you're using the Tobii legacy back-end, I would be very happy to implement the pupil size solution mentioned above.Cheers,
Edwin
Hi @Edwin,
I am using an older version of PyGaze where we only have the
tobiibackend because we run a Tobii T60. I think it's time for me to update the package, but it would be really nice to add pupillary measures to it!Han